I would definitely agree with you Sam about the build quality and the sound. Performance is top notch but H/K should have stuck with the same build quality as the 430, 630, ect. receivers. I also had a buddy who had a 680i and he said it was such a basket case it ended up in the dumpster after being on the bench 4 times. Sounds like this series was prone to reliability issues. Sam, do you know what these issues are attributed to? I would like to give mine preventative maintenance. There is however one thing I do know and that is I really love my 430 twin and anticipate keeping it for quite a long time because they were built to last.